1. Field
The present disclosure relates to a cathode for lithium air batteries, lithium air batteries including the same, and methods of manufacturing the cathodes for lithium air batteries.
2. Description of the Related Art
Lithium air batteries can include an anode which is capable of intercalating and deintercalating lithium, a cathode which oxidizes and reduces oxygen form the air, and a lithium ion conductive medium between the cathodes and the anodes.
In the lithium air battery, lithium is used as an anode, and air is used as a cathode active material, and thus the cathode active material does not need to be stored in the battery. Because the cathode active material does not need to be stored in the battery, a lithium air battery with a high capacity may be obtained. Lithium air batteries have a very high theoretical energy density per unit weight, e.g., 3,500 watt-hours per kilogram (Wh/kg) or greater, which is approximately 10 times greater than that of lithium ion batteries.
A lithium air battery uses, as an electrolyte, a liquid electrolyte or a solid electrolyte.
In this regard, the solid electrolyte has a lower ionic conductivity than the liquid electrolyte, and has poorer wettability at an interface thereof with a carbonaceous conductive material or the like. In addition, the solid electrolyte is squeezed out by lithium oxide formed in an air electrode during battery discharging and charging. It is difficult for the squeezed-out solid electrolyte to return and accordingly, reversible charging and discharging processes may be difficult. Moreover, when a lithium air battery operates at a high temperature, e.g., 60° C. or higher, there are problems with thermal stability and reversible charge/discharge characteristics.
Therefore, there is a need to develop a method of enhancing thermal stability and charge/discharge characteristics at high temperatures of a lithium air battery including a solid electrolyte.